1. Field of the Invention
The invention relates generally to optical heterodyning systems and, in particular, to a continuously variable delay line employing an acousto-optical cell and a beam translator such as disclosed in Ser. No. 274,576 filed concurrently herewith and incorporated herein by reference.
2. Description of the Prior Art
Optical heterodyning is known in the prior art. For example, U.S. Pat. No. 4,097,110 describes deep polarization measurement by optical heterodyning. A signal component polarized in one direction and a frequency shifted local oscillator component polarized in the same direction are formed from signal and reference components, respectively, of an incident beam. These components are optically heterodyned at a detector.